Well, look at it this way; the soundwaves tell the wounds to heal, right?

[he points to his head.]

If they told your brain to think differently, even if it was healthier, then technically they'd be taking over your mind, wouldn't they? That's a lot more dangerous. If it went wrong, I could hurt someone physically as well as mentally and they might end up even worse off because of what I'd done. I'd also be denying them their agency to recover naturally and come to terms with their own feelings.

I get it if you don't wanna talk about it to me, though. We just met! It's a real personal topic.